PF Train Motor vs L-Motor

[TF Twitch]

I am working on a 4-8-4 steam locomotive and have been wondering how to power it. Through some simple modifications it can either use two 88002 Train Motors under the tender or two 88003 L-Motors inside the boiler. It will use a 1:1 ratio using 12-tooth bevel gears. My question is which setup would be ideal? I personally like the L-Motor setup since it drives the actual driving wheels and I can use more realistic looking trucks for the tender. Using tender power would be more reliable since I do not have to worry about gears slipping or becoming unaligned.

Any information and advice is welcome.

[TF Twitch]

I currently use one PF Train Motor with my Emerald Night locomotive, and it pulls a rake of five coaches just fine. Based on that I know that two motors will be okay, even with the additional weight of a larger locomotive. I bring up using L-Motors inside the boiler since it would power the driving wheels and be more realistic. With the Train Motor setup all of the Power Function elements are in the tender to add weight for traction.

[ust60]

Hi TF Twitch,

In the first video work only two 88003 in the boiler of the BR 23

In the second video, after 1min 30 sec, the BR 01 at work two 9V Power Functions M works only for the beautiful

Optics, large drive wheels in the boiler of the BR 01

and under the tender for the pulling force two old 9 volt (two new 88002 are somewhat strong as two old 9 volt motors)

[jtlan]

I am working on a 4-8-4 steam locomotive and have been wondering how to power it. Through some simple modifications it can either use two 88002 Train Motors under the tender or two 88003 L-Motors inside the boiler. It will use a 1:1 ratio using 12-tooth bevel gears. My question is which setup would be ideal? I personally like the L-Motor setup since it drives the actual driving wheels and I can use more realistic looking trucks for the tender. Using tender power would be more reliable since I do not have to worry about gears slipping or becoming unaligned.

Any information and advice is welcome.

I doubt there will be any gear slipping problems -- if there are, it's an indication that your framing structure isn't strong enough. Unless your goal is to go screaming around the track at top speed, the L motors are going to be way better than the train motors because they can put out good power at a sedate speed. I'd actually even vouch for lower than 1:1 gearing.

You can see some power-testing results here. Unfortunately I haven't yet run any tests with the PF train motor.

[TF Twitch]

To those that answered, thank you. So from what I gather that the twin L-Motor setup is superior unless I want to go crazy fast? But at moderate to semi-fast the L-Motors are the way to go, and crazy fast go for the Train Motors?

Here is my proposal for a twin L-Motor configuration:

By learning from a previous failed attempt at putting an M-Motor inside the Emerald Night, I realized that I need to stabilize the vertical drive shaft. In an earlier attempt, the vertical drive shaft slipped off of the singular horizontal drive shaft (which then drove the driving wheels). The earlier design only had the single M-Motor with the "C" bracket. Here I added a drive shaft stabilizer of sorts. The pieces that are highlighted in red are connected by an axle peg ( + the entire length) to prevent the stabilizing piece from shifting. I hope that this surgically inserted assembly solves any issues that I have with the vertical drive shaft slip.

Edited March 3, 2015 by TF Twitch

[jtlan]

To those that answered, thank you. So from what I gather that the twin L-Motor setup is superior unless I want to go crazy fast? But at moderate to semi-fast the L-Motors are the way to go, and crazy fast go for the Train Motors?

Here is my proposal for a twin L-Motor configuration:

By learning from a previous failed attempt at putting an M-Motor inside the Emerald Night, I realized that I need to stabilize the vertical drive shaft. In an earlier attempt, the vertical drive shaft slipped off of the singular horizontal drive shaft (which then drove the driving wheels). The earlier design only had the single M-Motor with the "C" bracket. Here I added a drive shaft stabilizer of sorts. The pieces that are highlighted in red are connected by an axle peg ( + the entire length) to prevent the stabilizing piece from shifting. I hope that this surgically inserted assembly solves any issues that I have with the vertical drive shaft slip.

Unless you have something that keeps the lower bevel gear on the vertical shaft from moving, with this setup it looks like that gear will just skip upwards and stop driving the wheels. I would suggest using some of the older Technic beams, frames, and plates, if you can spare the room, as that often with give better support. Alternatively, insert a spacer between the lower bevel gear and the red supports -- it looks like it might be a bit too small for a half-bushing though.

[TF Twitch]

Unless you have something that keeps the lower bevel gear on the vertical shaft from moving, with this setup it looks like that gear will just skip upwards and stop driving the wheels. I would suggest using some of the older Technic beams, frames, and plates, if you can spare the room, as that often with give better support. Alternatively, insert a spacer between the lower bevel gear and the red supports -- it looks like it might be a bit too small for a half-bushing though.

I appreciate the feedback! I was able to move the lower bevel gear downward on the vertical drive shaft and insert a half-bushing. Thank you for the idea, that makes it more snug!

[legoman666]

I have a bunch of locomotive's that each have 2 L motors and AA battery packs. Even with custom steel wheels that have less traction than Lego's stock wheels, each locomotive can pull 16' of 7/8W rolling stock without bogging down. My loco with 2 PF train motors goes too fast through straights and almost stops through curves.

[zephyr1934]

If you have room, I'd suggest replacing the red part with it's 180 degree cousin,

Depending on what the hidden parts are, instead of the bushing shown in a later rendering, you might be able to use a technic plate (2x4?) to hold the lower bevel gear in place... oh, wait, it looks like you are half a stud off for that... stinkin physics.

[TF Twitch]

I have a bunch of locomotive's that each have 2 L motors and AA battery packs. Even with custom steel wheels that have less traction than Lego's stock wheels, each locomotive can pull 16' of 7/8W rolling stock without bogging down. My loco with 2 PF train motors goes too fast through straights and almost stops through curves.

Thank you for that information, that really does make a difference.

If you have room, I'd suggest replacing the red part with it's 180 degree cousin,

Depending on what the hidden parts are, instead of the bushing shown in a later rendering, you might be able to use a technic plate (2x4?) to hold the lower bevel gear in place... oh, wait, it looks like you are half a stud off for that... stinkin physics.

I also considered the technic plate option, but yes the vertical drive shaft is offset thanks to the "C" bracket. I also considered using the piece that you have shown, but that requires some extensive modification underneath the front L-Motor. It could be done, but it may compromise the original integrity of the frame. The red parts are connected together with an axle, not a pin, so they are not going to rotate at all.